Cut-throat business

Stephen Sondheim's 'Sweeney Todd' was a flop on its West End première. Yet 25 years later it is acknowledged as his masterpiece. He tells Sarah Crompton why he thinks it has endured

Few people associated with the first production of Stephen Sondheim's Sweeney Todd expected it to be a hit. They loved the dark, taut tale of the murderous barber of Fleet Street but feared they might be alone.

Len Cariou, the original Sweeney, wondered whether the audience would get it; director Hal Prince thought it was a noble experiment doomed to fail.

Yet, 25 years on, Sweeney Todd is habitually referred to as Sondheim's masterpiece - a show so dramatically and musically indestructible that it can be staged by opera companies, fringe theatres or amateur groups and still emerge triumphantly unscathed.

This week, a radical new staging of this brutal melodrama, set in Victorian times, transfers to the West End. John Doyle's version, originally for the Watermill Theatre, even dispenses with the totemic chair on which Sweeney traditionally dispatches his victims.

Sondheim, who has seen a tape, approves. "It's so original," he says. "I have no idea how it will strike people because it is so unusual."

This enthusiasm on the part of a composer for a whole-hearted restaging of his work is unusual. Traditionally, musical revivals preserve in aspic all the qualities people loved about the original.

But Sondheim emphasises his liking for change. "Obviously, I don't want them to distort the piece. But what is fun is to see people do different things with something you've written. That's what makes the theatre different from the movies."

Sweeney Todd offers rich material for such rethinking. "Most musicals don't have a particularly strong story," says Sondheim. "The popular ones have a lot of good songs and moments, but you can't do most of them many different ways. Because of its melodrama and because of its setting, Sweeney offers many different ways to try it.

"I remember when I was at college, one of the English professors made what seems an obvious point, but it wasn't obvious to me at the age of 17, that one of the things that keeps Hamlet alive is that every generation brings something new to the performance. It isn't just the poetry; it's that every time you do Hamlet you can take a different view of it - and that's what keeps theatre alive.

"With musicals, the audience tend to want to see what they've seen before. Whereas people who go to Hamlet want to see something different."

That comment is revealing. Sondheim's entire, varied career has been based on the premise that you can use the musical as a vehicle to explore complex themes and tell uncompromising stories. He works like a playwright rather than a musical composer.

This tendency was in his career from the beginning. At 17, he was collaborating with his mentor Oscar Hammerstein on Allegro, a self-consciously experimental show about a doctor who loses his vocation. His first Broadway outing was as lyricist on West Side Story, which was "hardly an ordinary musical either".

"I have just accepted," he says, "that I do musicals that quite often strike people as odd and unusual."

In this context, a musical about a slash-happy barber and his crazed accomplice who bakes his victims into pies did not seem like a brave step, more a logical progression.

When writing the music for Sweeney, Sondheim was strongly influenced by the music of Hitchcock's composer Bernard Herrmann.

"In a way it's a tribute to him," he says. "I just wanted to write a piece to scare the audience, and that's why there is so much music in it. As you can tell from any Hitchcock movie, it's the constant presence of music that gives you the chills even if nothing particular is happening on the screen."

That was always how Sondheim saw Sweeney Todd. It was his shilling shocker, a chamber piece to frighten audiences out of their wits. But it was staged at the end of his terrific initial run of collaborations with Hal Prince, a sequence that changed the face of the modern musical, beginning with the acerbic Company in 1971, through Follies, A Little Night Music, and Pacific Overtures in 1976.

When Prince heard Sweeney, he wanted to turn a small, scary story into a big production. "I thought, Well, somebody can always do it small, but when am I ever going to get a chance to have it done in high style by a man who is the master of a kind of epic theatre? What's to lose?"

It was this staging, with gantries and factory chimneys dwarfing the human action, that opened on Broadway in 1979. It got mainly good reviews, ran for more than 500 performances, and was, in Sondheim's words, "moderately popular", though it failed to make its money back. A year later, it came to the cavernous Theatre Royal in Drury Lane - and sank like a stone, closing after 157 performances.

Sondheim has always been hurt by this reception. "It was my love letter to London." But now, he thinks he understands. "A friend of mine, the playwright John Guare, said that it was as if the British had come to the States and done a serious musical of I Love Lucy.

"And we would think, Don't they know that's a silly comedy? Well, I think maybe, with Sweeney Todd, people thought that the Americans were taking a melodrama just too seriously. How pretentious! "

But the power of Sweeney Todd lodged in the mind of everyone who saw it - and has given it a remarkably successful afterlife. While professional directors such as Declan Donnellan have turned it back into a haunting chamber piece, and opera houses have given it the grand treatment, it has also proved popular with amateur groups.

Sondheim explains: "It gives people a chance to exercise their chops - to really sing with a capital S and really act with a capital A, the way one does in melodrama. So they get to chew the scenery and chew the music at the same time. I think that's what it is. It's fun to do."

That said, he admits: "I didn't really expect it to be done a lot because of the vocal demands. But I must tell you, that was always my prediction about West Side Story. I said, This is not going to be done very much because of all the dance. Boy, was I wrong."

Sondheim says that his two favourite forms are melodrama and farce because "they are heightened reality. And that's my idea of terrific theatre."

It is therefore appropriate that the new production of Sweeney will be running concurrently with the National Theatre's restaging of one of Sondheim's early works, A Funny Thing Happened on the Way to the Forum. This is another source of satisfaction: "I loved that show a lot."

So he works on, still at 74 pursuing his own vision, taking brave and unexpected steps - just as he did 25 years ago when he turned Christopher Bond's play about Sweeney Todd into a resonant musical masterpiece.

"When you write a show, you don't really think about attracting audiences. You can't either write down to them or up to them, you just have to tell the story and hope that they're interested in the story the way you are and in the way you tell it. And if they're not, there's nothing you can do anyway."